Hewlett Avenue CSO
Storm overflow operated by United Utilities. The source names Tanyard Brook as the receiving water.
- 27
- Spills in 2025
- 32
- Recorded hours
- 100%
- Monitor operation
- 2
- Years listed
The reported spill count was the same as in 2024. This compares event counts, not discharge volume.
We do not have a live report for this outlet. Its annual spill records are shown below.
How it compares in 2025
Hewlett Avenue CSO recorded 27 spills in 2025. That is more than 71% of the 14,239 overflows in England with a reported figure, and ranks 3,910th nationally. Among United Utilities overflows it ranks 844th of 2,270; the median United Utilities overflow recorded 15 spills. On the Yarrow DS Big Lodge Water waterbody it ranks 6th of 19.
| Group | Rank by spills | Median spills | Median hours |
|---|---|---|---|
| This outlet | – | 27 | 32 |
| England | 3,910th of 14,239 | 11 | 22.3 |
| United Utilities | 844th of 2,270 | 15 | 29.1 |
| Yarrow DS Big Lodge Water | 6th of 19 | 18 | 19.8 |
Rank 1 has the most spills. Equal counts share a rank. Only overflows with a reported count are ranked. Counts do not measure volume, so a higher rank does not mean more sewage.
Annual spill history
| Year | Spills | Duration | Monitor operation | Source |
|---|---|---|---|---|
| 2025 | 27 | 32 hours | 100% | Official data |
| 2024 | 27 | 35.3 hours | 100% | Official data |
A missing figure means the source did not provide a usable value. A zero is shown as zero. Monitor operation below 90% can make comparison less reliable.
Outlet details
- Water company
- United Utilities
- Outlet type
- Storm overflow on the sewer network
- Permit
- NPSWQD010698
- Activity reference
- A1
- Grid reference
- SD5579414219
- Waterbody ID
- GB112070064952Official waterbody record ↗
- Location source
- Official annual grid reference
- Location precision
- About 1 metres
- Location note
- Unknown
About the name and type
The annual return lists this asset as “SO on sewer network”: storm overflow on the sewer network. The return places this overflow on the sewer network.
The waterbody link opens the Environment Agency record for the exact ID in the return. It is a source lookup; we do not import its classification.
Where it is
The recorded position is about 0.6 km north-west of the Coppull reference point in the ONS built-up areas data.
Area and water pages
Check the official record
Public access to this outlet is unknown. Do not enter restricted land or use this page as a route guide.
Open official source ↗Other outlet records nearby
- Mavis Drive CSOCurrent status unknown
United Utilities · Clancutt Brook
- Cowling Farm CSOCurrent status unknown
United Utilities · Clancutt Brook
- Brook Lane PSCurrent status unknown
United Utilities · unnamed tributary of Syd Brook
- Clover Road PSCurrent status unknown
United Utilities · River Yarrow
Questions about Hewlett Avenue CSO
- Who operates Hewlett Avenue CSO?
- United Utilities is the operator named in the annual record. The permit reference is NPSWQD010698.
- Where does Hewlett Avenue CSO discharge?
- The source names Tanyard Brook as the receiving water. This does not show how far a discharge travelled.
- How many times did Hewlett Avenue CSO spill in 2025?
- The 2025 return records 27 counted spill events and 32 hours of recorded discharge. Spills are counted with the 12/24-hour method, so this is not a count of every start signal.
- Can I trust the 2025 figures for this outlet?
- The monitor worked for 100% of the reporting period, so the annual figures cover most of the year. They still do not measure discharge volume.
- Is Hewlett Avenue CSO discharging right now?
- This record is not matched to a company live feed, so we cannot show a current report. Only the annual figures are available for this outlet.
- How accurate is the map marker?
- The marker comes from the grid reference in the official annual return, which is accurate to about 1 metres. It shows the recorded outlet position, not the extent of any discharge.
- What kind of outlet is Hewlett Avenue CSO?
- The annual return lists the asset type as “SO on sewer network”, which means storm overflow on the sewer network. The return places this overflow on the sewer network.
- How does Hewlett Avenue CSO compare with other overflows?
- Hewlett Avenue CSO recorded 27 spills in 2025. That is more than 71% of the 14,239 overflows in England with a reported figure, and ranks 3,910th nationally. Among United Utilities overflows it ranks 844th of 2,270; the median United Utilities overflow recorded 15 spills. On the Yarrow DS Big Lodge Water waterbody it ranks 6th of 19. Ranks compare counted spill events only. They do not compare volume or harm.
- Does zero spills mean the water was safe?
- No. A zero means the annual return recorded zero counted spill events for this outlet and year. It is not a water-quality test, and pollution can come from other sources.